When you encounter this issue, the only thing to do is to actually re-install the software. You need to perform a fresh install for the application to actually have a chance of starting. Additionally, go to Start > Run > regedit. Navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\BlueStacks\Guests\Android and change the amount of RAM on the right side. Double click the string and switch to DECIMAL. Change the value according to the physical RAM installed. For example, if you have 4 GB of RAM, try to assign somewhere around 1-1,5 GB, but no more than 2 GB.